Method of making seamless tubes rich in zinc



Oct. .23 1923. HAYLSYB w. L. WOODWARD METHOD OF MAKING SEAMLESS TUBESRICH IN ZINC 7 Filed April 2, 1921 [III/IIIIIIIIIIIIIIIfiI/IIIIIIII/fi IW21. WWW-M,

Patented @ctt. 23, 1923.

when

Ulnar rare smear re.

1AM L. WOODWARD, OF LAKEWOOD, OHIO.

METHOD OF MAKING SEAMLESS TUBES RICH IN ZINC.

Application filed April 2,

' To all whom it may concern:

This invention relates to a novel method for making seamless tubes ofzinc or of an alloy rich in zinc.

It is well known that cast zinc is of crystalline structure, incapableof being rolled or drawn except under special conditions within welldefined limits and the object of my invention is to provide a cheap andsimple method ofproducing a seamless tube from a cast metal tubularbody, the finished product possessing ductility and malleabil-T ity sothat said tubes can be drawn, bent,

swaged or otherwise manipulated in the course of commercial fabricationin which a bendable or drawable tube is desired With these objects inview the invention consists in thesteps' hereinafter described and setforth in the appended claims. In the drawing I have diagrammaticallyoutlined the various steps of my process and in which Fig. 1 indicates alongitudinal section of a cast metal body of zinc or of 'an alloy richin zinc; Fig. 2 is a similar view illustrating the first treatment towhich said tubular body is subjected; Fig. 3 is a Sectional elevationillustrating the beginning of the second treatment and Fig. leis asimilar view illustrating the completion of the sec- 0nd treatment; Fig.5 is a longitudinal sectional view of the transformed tubular body andFig. 6 is a longitudinal sectional view of a seamless tube drawn fromthe transformed tubular body illustrated in Fig. 5; Figs. 7 and 8 aredetailed sectional views illustrating another manner of carrying out myimproved method and Fig. 9 is a still further modified form of carryingout the same.-

In carrying out my invention I provide a tubular body A of zinc or of analloy rich in zinc, said body being preferably cast in the form of-ablock and then bored centrally as indicated at A, but it will beunderstood that if desired the tubular body can be cast with the centralopening, but in practice I 1921. Serial No. 458,116.

have found it desirable to bore the same. The cast tubular body iscrystalline throughout and first of all I find it desirable tomechanically treat this cast metal tubular body to a limited extent andthis I do by arrangmg the same upon a suitable mandrel B and subjectingit to a slight hammering operation throughthe medium of a hammer Ooperated in any suitable manner. The tubular body thus subjected to thispreliminary mechan cal treatment is then preferably heated to aslightdegree,'that is from 200 to 300 degrees F. and is then subjected to acompressive action for the purpose of breakmg up the crystallinestructure and causing the molecules to re'-arrange themselves in suchform that the transformed tubular body will be malleable and ductile andcapable of being drawn out and worked in any desired manner without theapplication of heat, and in practice I prefer to place' the tubular bodyA after being subjected to the preliminary and mechanical treatment andthe slight heating operation within a strong inexpansible shellor'container D and then compress the same by means of a mandrel E havingthe tapered portion E and the extended portion E said extended portionbeing of a diameter to fit loosely within the bore of the tubular body Aand the mandrel from end to end, that is, the extended a portion E thetapered portion E and the main portion E are all very hard steel andhighly polished and by applying pressure at the rear end of this mandreland providing a suitable stop F at the opposite end of the shell andtubular body, I force the mandrel drel is forced throu h the slightlyheated tubular body, said bo y will be heated somewhat more from thefriction created by the passage of the mandrel and the smoothness of thesurface of the mandrel facilitates the compression of the walls of thetubular body and in effecting this compression I completely transformthe molecular structure of the tubular body and produce a tubular bodyA, the walls of which are much thinner than the tubular body A and thebore A thereof much larger than the bore A and the tubular body insteadof being of crystalline formation is of such structure that said tubularbody can be rolled or drawn out into tubular form as indicated at A inFig. 6 and all without the further application of heat, the compressiveaction of the mandrel serving to break up the crys talline structure andtransform the tubular body into one possessing malleability andductility in a high degree. There are other ways of accomplishing thissame compressing and transforming action and in Fig. 7 T have shown amoldeGr in which the tubular body His cast, there being a central core Ito poduce the necessary bore, a suitable plate being arranged at thebottom to prevent the metal escaping during the molding process. Afterthe zinc or material rich in zinc has cooled to the proper extent I apply a follower L to the top or rear thereof and apply strong pressurethereto, it being understood that the interior surface of the mold ishighly polished and likewise the central rod and when the pressure isapplied to the tubular cast metal body it is forced out in the form of atube as indicated at M and this tube thus forced out will be found topossess malleability and ductility in contradistinction to thecrystalline structure of the tubular body before the compressive forceis applied thereto and this cast metal body is preferably subjected tothe reliminary hammering or rollingoperation indicated in Fig; 2.

In Fig. 9 T have shown a still further modification in which the castmetal tubular body A is placed upon a suitable anvil N having a tubularrod Q extending up through the central bore of the tubular body and thenan inexpansible shell P having the tapering portion P and contractedbore P is forced down over and around the cast metal body A and duringthis operation the walls of the cast metal body are compressed aspreviously described, and during this compressive operation thecrystalline structure is broken up and a new body is created in whichthe walls are not only thinner but the structure thereof possessesmalleability and ductility so that the tubular body thus transformed canbe readily further drawn or worked in any manner similar to a tubepossessing malleability and ductility.

that T providea simple and highly eficient method of making seamlesstubes of zinc or of an alloy rich in zinc.

Having thus described my invention, what ll claim is: w

-1. The herein described method of making seamless tubes which consistsin providing a cast tubular body rich in zinc, subjecting said casttubular body to mechanical treatment, then heating said tubular body sotreated and then subjecting the walls of said tubular bodyto lateralcompression.

2. The herein described method of making seamless tubes which consistsin providing a cast tubular body rich in zinc, mechanically treatingsaid cast tubular body, then heating said tubular body so treated, thensubjecting the walls of said tubular body to lateral compression totransform the crystalline structure of thecast tubular body and providethe tubular body with walls of reduced thickness, the tubular body as awhole after such treatment possessing malleability and ductility.

3. The herein described method of making seamless tubes which consistsin first providing a cast metal tubular body of crystalline structure,subjecting said tubular body to mechanical treatment, then heating saidtubularbody so treated, then breaking up the crystalline structure andtransforming the tubular body into one possessing ductility andmalleability by subjecting the walls of saidtubular body to lateraloompress'ion and then drawing said tubular body into a tube of reduceddiameter.

4. The. herein described method of breaking up the crystalline structureof a cast metal tubular body and rearranging the molecules thereof so asto provide a tubular body possessing ductility and malleability Whichconsists in first mechanically treating said cast metal tubular body,then heating the same and finally subjectingithe walls of said tubularbody to lateral compression and then drawing said body into a tube ofless diameter. i

5. The herein described method of transforming a cast metal tubular bodyof crystalline structure into a tube possessing malleability andductility by breaking up the crystalline formation and rearranging themolecules which consists in first mechanically treating the cast metalcrystalline tubular body, then heating the same, then subjectingthewalls of said tubular body to lateral compression and finally drawingsaid ,tubular'body to change the diameter thereof. It will be understoodof course that the In testimony whereof, I hereunto afiix my signature.

WILLIAM L. woonwaan.

